TNF and endothelial dysfunction: Among these, tumor necrosis factor-α (TNFα) has been linked with reduced insulin sensitivity and decreased endothelial NO synthase expression in cultured endothelial cells[5], and interleukin −6 (IL-6) is implicated in endothelial dysfunction and vascular inflammation through several mechanisms, including induced expression of monocyte chemotactic protein-1 (MCP-1)[6].